The viscoelastic nature of living cells is crucial for their biological function. Experiments using various techniques have shown that cells present solid- and liquid-like behavior. Over a wide frequency range (0.1Hz-100Hz), elastic and viscous moduli are coupled and follow a weak power law of exponent 0.05-0.035, with elastic stresses dominating over viscous stresses (1-4). This response is incompatible with one typical relaxation time and has been explained in terms of soft glassy rheology with a spectrum of relaxation times (1). At higher frequencies, semiflexible polymer theory and experiments suggest an exponent of ∼0.75 (5, 6). However, experimental data on cells at high rates is still limited due to experimental limitations. The aim of this work was to overcome this limitation by adapting a high-speed atomic force microscope to extend the frequency range up to 120 kHz, about two orders of magnitude faster than previous studies. Applying low amplitude oscillations over five decades (1Hz-120kHz), we probe the microrheology of living fibroblasts under different cytoskeletal interventions. Unlike previous studies, our results suggest that the weak power law extends to frequencies up to ∼10kHz. At higher frequencies, the data suggest a power law of exponent between 0.5 and 0.85, modulated upon intervention of the cytoskeleton activity.